Virtualized storage delivers business continuity and more

When Stikeman Elliot, a Canadian law firm with a global footprint, first adopted server virtualization “full throttle” they found backups a time-consuming chore: 24 to 48 hours for the entire virtual server pool. By deploying DataCore SANsymphony-V storage hypervisors at their Montreal and Toronto hubs, the IT team was not only able to eliminate the need for tape backups but provide much greater business continuity through high availability and improved disaster recovery (DR).

Date: 16 Jan 2012

Stikeman Elliott was also able to get more out of its existing storage investments: both higher performance and a longer service life. SANsymphony-V can combine any storage – from storage area networks (SANs) to re-purposed SCSI drives on an x86 server – into a single, easily-managed high-performance virtual storage pool with auto-tiering.

Committed to Server VirtualizationStikeman Elliott’s IT team includes two network systems groups – one in Montreal, and the other in Toronto. Stikeman Elliott has heavily invested in IT and has committed itself to server virtualization in order to support the firm’s leading-edge knowledge management and project management systems. Today, 100 percent of their storage capacity is devoted to virtualized server data. However, backing up the virtual machines had become a serious challenge; backing up the whole pool of virtual servers to tape or disk could take anywhere from 24 to 48 hours or days. Marco Magini, a network systems specialist at Stikeman Elliott, was tasked to find a better way to speed up the process.

Looking for Faster Backups, Finding High Availability and a Lot More“The firm had plenty of physical storage available, so it was not storage virtualization per se that was of paramount interest to us,” Magini says. “We were focused on reducing the time it took to back up and recover our virtual servers.”

With DataCore’s storage hypervisor, Magini found more than he’d expected. First off, the extensive data protection capabilities built into SANsymphony-V not only reduced virtual machine backup time to zero but made tape backup unnecessary.
Zero-Time Backups and Business Continuity with Continuous Data Protection
DataCore’s Continuous Data Protection (CDP) protects against data corruption with the ability to roll storage state back to a specific write. Furthermore, SANsymphony-V provides high availability (HA) based on synchronous mirroring and transparent failover to protect against local failures. The Montreal office hosts two SANsymphony-V synchronously-mirrored nodes linked via Fibre Channel. The secondary node represents a perfect copy of the main virtual SAN provided by the storage hypervisor – with CDP, effectively an automatic write-granular backup. Backup time is zero, since any previous virtual machine state can be recreated at any time from either server. It also saves IT time, since there is no need to manage a backup schedule.

“With DataCore’s high-availability capability, we have circumvented the need for back-ups with true business continuity,” explains Magini. “If the main storage goes down, the secondary storage that is already active will pick up the full load in seconds,” he says.

A third SANsymphony-V server in Toronto also strengthens Stikeman Elliott’s disaster recovery (DR) strategy with remote site asynchronous IP mirroring to make sure critical application data in the firm’s offices is safe against large-scale events. Eventually, the firm intends to extend the DataCore platform to support more applications.

“We started slowly,” says Magini, “but as we became more familiar with the intelligence and stability of the DataCore storage hypervisor, we put more and more mission-critical systems on top of it and now have almost all of our systems behind it. We have every confidence that SANsymphony-V can handle anything we give it.”

Orphaned Disks Make a New SAN to Get More From Storage Investments
As with many firms, Stikeman Elliott’s server virtualization process had orphaned the SCSI disks in the many physical servers eliminated by consolidation. Magini praises DataCore’s storage hypervisor for its ability to breathe new life into these old disks and enabling Stikeman Elliott to get maximum value from its storage assets. “SANsymphony-V doesn’t care what you hook up to it,” explains Magini. “It will take anything from SAN boxes to SCSI disks in a rack to a bunch of iPods on a USB hub and make them all one big storage pool.”

This not only gave Stikeman Elliot more efficient management of existing storage arrays and SANs, but meant a continued career for almost two cabinet’s worth of orphaned disks. Magini has repurposed about 50 SCSI drives ranging from 72 to 300 GB in size by connecting them to the DataCore servers, ending up with an extra 10TB of storage. To applications, these disks, by themselves incapable of network operation, are now a seamless part of the virtual storage infrastructure created by the DataCore platform right alongside the SANs. With DataCore’s thin provisioning, applications immediately get just the right size virtual disks needed from the storage pool without burdening IT with storage management details.

“We can literally use disks or storage systems until they die – until the last spindle,” adds Magini. “Because we have redundancy that is seamless and transparent, we can get every last second of use out of what we have.”

DataCore has also made Stikeman Elliott independent of the server platform their storage hypervisor runs on. “The beauty of DataCore’s software-based storage virtualization is that it doesn’t dictate to the customer or the IT solutions provider what platform the software has to run on,” explains Lefort. “The customer chooses the platform – in this case, HP ProLiant machines – based on their own experience and preferences. DataCore gives them latitude to choose the brand, the model and the size of the server that becomes the storage controller.”

All This and Better Performance, Too
With SANsymphony-V’s high speed Level-1 caching software, there’s no tradeoff between all these advantages and storage performance. “One of the things we love with DataCore is that the RAM we put in our dedicated SANsymphony-V servers becomes a very efficient cache for any storage we have connected to it. We get everything we were looking for business-wise plus better performance.” The SANsymphony-V cache, which can use up to a terabyte of RAM on a 64-bit server, uses advanced write-coalescence and pre-fetch read algorithms to deliver an average response time of less than 20 microseconds. This is much faster than the average of 250-300 microsecond time delivered by typical array-based L2 caches or the 4000-6000 microseconds characteristic of disk drives themselves. In general, a simple volume presented by the SANsymphony-V storage hypervisor and its cache will perform at twice the throughput speed of raw disk devices.

At Stikeman Elliott, this added performance showed up in a couple of ways. The firm’s virtual servers on SCSI drives originally took at least a full minute to boot. When the IT team put those virtual servers on the HP arrays, boot time fell to under thirty seconds. Now that the DataCore storage hypervisor has taken over storage operations, virtual servers boot in less than ten seconds. Magini is seeing similar or better results with applications. “Workloads with a high I/O demand get super-charged on DataCore’s storage hypervisor. We have seen a tremendous gain in performance with certain applications and databases. It is hard not to notice – you just get the data much quicker.”

“Although we started out looking for solution to a backup problem, we ended up with a lot more from DataCore,” says Magini. “This one investment provided a very cost effective way for us to meet or exceed several business goals. Backup is no longer an issue. We’ve improved our resilience in the face of disaster. Best of all, combined with a robust vSphere HA infrastructure spread across two physical sites with multi-pathing, SANsymphony-V’s high availability gives us non-stop business operations. All this, plus both higher performance and a higher return from our storage investments.”
IT Environment

Stikeman Elliott uses HP servers and storage. Both the primary and secondary sites run on HP ProLiant DL 38x servers with 32 GBs of RAM, complemented by a vSphere infrastructure composed of eight hosts split into two high-availability clusters. The storage layer has two main storage SANs – one EVA 4400 and one P6500. The rest is a mixture of devices unified into a single virtual pool by the DataCore storage hypervisor: an EVA 3000, and MSA2212fc, and a number of NAS boxes, FC drives, FATA drives, SAS drives, and JBOD SCSI drives from 72 to 300GB.